Method for integrated treatment of red mud

FIELD: chemistry.

SUBSTANCE: method includes magnetic-gravitational treatment of red mud. The starting red mud first undergoes dispergation in the presence of sodium hexametaphosphate in a rotary-pulsation apparatus, followed by low-gradient wet magnetic separation in a field with strength of 0.1-0.15 T to obtain a magnetite and a bulk concentrate, subjecting the bulk concentrate to high-gradient magnetic separation in two steps in a field with a strength of not less than 1.2 T to extract magnetic and nonmagnetic fractions, subjecting the magnetic fraction to gravitational concentration on a concentration table to obtain a hematite concentrate and tailings, combining the nonmagnetic fraction with the tailings from gravitational concentration and performing two-step selective flocculation in the presence of a flocculant to separate a component which primarily consists of aluminium and silicon oxides from an iron-containing product, which is concentrated by high-gradient magnetic separation with field strength of 0.5-0.7 T to obtain an additional iron-containing product, which is combined with the hematite concentrate to obtain an iron-containing concentrate, and residual aluminosilicates which are combined with the component primarily consisting of aluminium and silicon oxides to obtain an aluminosilicate product.

EFFECT: high degree of extraction of iron into an iron-containing product and obtaining an aluminosilicate product with high iron content.

5 cl

 

The invention relates to the field of metallurgy and can be used in the processing of red mud is a waste alumina production - for iron concentrate and aluminosilicate product that can be used for the manufacture of construction materials.

There is a method of processing red mud from alumina production, including the production of a slurry of red mud, the classification of the pulp, class of particles of 40-60 microns for the Department alumosilicates fraction with a particle size of more than 40-60 μm and high-gradient magnetic separation of particles less than 40-60 μm at pH slurry of 1.5 to 4 and a magnetic field strength of 30 to 80 kA/m (0,4-1,0 T) getting rich scandium-containing magnetic concentrate (output 4-7%, Fe2O3- 65-76%) (USSR author's certificate 1715874, IPC C22B 59/00, C01F 7/02, op. 29.02.1992).

The disadvantage of this method is not a high yield of the resulting iron-containing product, due to the fact that part of the iron remains in the particles larger than 40-60 μm, which are alumosilicate faction.

The known method for integrated processing of red mud, including the filing of the red sludge in the form of a pulp with an alkaline medium, magnetic sedimentation separator separating ferromagnetic components (iron is the first product from the pulp, activation of the pulp and electrophoretic separation for separation of negatively charged particles, mainly consisting of silicon dioxide, and positively charged particles, the bulk of which are oxides of aluminum and titanium, with the last translation in the pulp and subsequent electrophoretic separation of particles of oxides of aluminum and titanium (RF patent 2198943, IPC C22B 7/00, 34/00, op. 20.02.2003).

The disadvantage of this invention is not a high quality iron product and the complexity of the method, providing for two-phase electrophoretic separation.

There is a method of enrichment of old tailings tailings, including their processing with the release of iron minerals, with old tailings for processing serves as a pulp, and processing is carried out by protective screening pulp, its classification according to the class of 0.16 μm, a primary and a cleaner cell magnetic separation with grain size less than of 0.16 μm, dehydration of the products obtained, both magnetic separation of lead in an inhomogeneous magnetic field with induction of 0.4 T, and the slurry in a magnetic field serves at a rate of 0.2-0.3 m/s the resulting concentrate contains 66% iron, and the tails from both separators contain 10-12% iron and after dehydration is used for the production of building mater what Alov (patent of Ukraine # 26931, IPC B03C 1/00, B03B 7/00, op. 29.12.1999).

The disadvantage of this method is not a high yield of the resulting iron-containing product, due to the fact that part of the iron remains in the particles more of 0.16 μm, representing the tails of separation.

A method of obtaining marketable products from red mud by magnetic gravity separation adopted for the prototype, including the classification of the original sludge granulometric composition of obtaining clay fraction and sand, high-gradient magnetic separation of sand separating the magnetic iron concentrate) and nonmagnetic fractions, followed by gravity separation of non-magnetic fractions in a centrifugal field or concentration table with getting heavy fraction, representing compounds of iron, zircon, rutile and gold, and light fraction containing silicates. The collective output of the iron concentrate is 15-18%, the content of Fetotal- 51% (Bragin YU.N., Dobrovolskaya TI, Borisov V.V. and other New technology of producing marketable products from red mud. "The state of problems and directions for use in the national economy red mud". Collection of scientific papers, Nikolaev, 1998, p.23-30).

The disadvantages of this method are not a high yield of iron in the concentrate due to C who lnym allocation of iron, contained in the magnetite and silicate refractory mineral formations, in the magnetic product with separation and heavy fraction of the gravitational enrichment, and obtaining as a light fraction product requiring processing for future use.

The technical result of the invention is to increase the output of iron ore concentrate with a high content of iron and getting aluminosilicate product suitable for further use.

This result is achieved in that in the method for integrated processing of red mud containing hematite, chamosite, goethite, magnetite, silicates, by means of magneto-gravity processing of obtaining iron concentrate and alumina products, according to the invention of the original red mud previously subjected to dispersion in the presence of sodium hexametaphosphate in a rotary pulsation apparatus, followed by discordantly wet magnetic separation field strength of 0.1-0.15 Tesla obtaining magnetite and collective concentrate bulk concentrate is subjected to high-gradient magnetic separation in two stages in the field of not less than 1.2 TL with removing the magnetic and nonmagnetic fractions, magnetic fraction is subjected to gravity is the enrichment in the concentration table with getting hematite concentrate and tailings, and the non-magnetic fraction unite with tails gravity concentration and subjected to two-stage selective flocculation in the presence of flocculant to separate component, consisting mainly of oxides of aluminum and silicon from iron-containing product, which enrich the high-gradient magnetic separation at a field strength of 0.5-0.7 T with additional iron-containing product, the latter combined with the hematite concentrate to produce iron concentrate and residual silicates, which unite with the component, consisting mainly of oxides of aluminum and silicon with getting aluminosilicate product. This discordantly wet magnetic separation is carried out at a ratio W:T=3÷4:1, the sodium hexametaphosphate is used in the amount of 100-200 g/t tails gravity separation prior to selective flocculation is subjected to screening to a particle size of minus 0,032 mm, and as a flocculant use hydrolyzed polyacrylamide in the amount of 3-5 g/so

The proposed set of operations of the proposed method is aimed at increasing output of iron ore concentrate and the maximum extraction of iron from red mud that has a complex structure with a large number of mineral phases in the concentrate:

- dispersion make in rotary-pulsation is the first device in the presence of sodium hexametaphosphate - for disaggregation of flocs, which included grains of iron-containing minerals, and removal of oxide films;

- niskogradnja wet magnetic separation to highlight Selfnominated minerals (magnetite);

- two-stage wet high gradient magnetic separation for separation of weakly magnetic minerals hematite, chamosite, goethite, and increase the output of iron-containing product;

- gravitational enrichment to a concentration buffet magnetic fraction allocated to the second stage separation, for separation of hematite from chamosite;

- screening of non-magnetic product class to 0.032 mm;

- dispersion make undersize product screen size minus 0,032 mm;

selective flocculation of two-phase dispersed non-magnetic component obtained in the second stage high-gradient magnetic separation, is designed for flocculation of finely disperse silica and silicates, followed by the separation of the oxides of aluminum and silicon from iron-bearing minerals at concentrations of iron oxides and increased output of iron ore concentrate;

wet magnetic separation in a high magnetic field for additional allocations flokulirovannym iron minerals.

Preliminary dispersion make the original red mud in the presence of sodium hexametaphosphate in the count is the number of 100-200 g/t provides a disaggregation of flocs which included grains of iron-containing minerals, reduced reagent consumption, affects the dispersion make slimes, and increased consumption does not improve dispersion and is impractical.

The magnetic field strength of 0.1-0.15 Tesla when carrying out the separation of dispersed sludge allows not only to highlight the magnetite, but also creates conditions for more efficient magnetic separation in a strong field with a strength of not less than 1.2 to 1.4 T with separation of weakly magnetic fraction (hematite product).

The selective flocculation in the presence of flocculant - hydrolyzed polyacrylamide, taken in an amount of 3-5 g/t, provides optimum flocculation of minerals.

Removing sfokusirovannykh iron-bearing minerals at a field strength of 0.5-0.7 T allows you to extract iron in additional iron-containing product, increases the extraction of iron from red mud, and also provides a receiving aluminosilicate product with low content of iron.

Thus, the claimed method provides integrated waste in the production of alumina - red-sludge - to produce high-quality iron-containing aluminosilicate products suitable for further use.

The method is as follows.

Original red the sludge (Fe 30-35%, size 80% CL - 5.0 µm) is subjected to dispersion with sodium hexametaphosphate (GMF-100-200 g/t) in the rotary pulsation apparatus for disaggregation of flocs and removal of oxide film, followed by discordantly magnetic separation field strength of 0.1-0.15 T magnetic separator PBM emitting in sinnamahoning fraction of magnetite concentrate (Fe 52,7-53,0%) and in the non-magnetic fraction of the bulk concentrate. The bulk concentrate is subjected to high-gradient magnetic separation field intensity higher than the 1.2 TL (optimally a 1.4 Tesla) magnetic separator "Humboldt" in two stages with obtaining magnetic fraction (Fe - 41,5%output % 23,5%) and non-magnetic fractions, representing mainly the oxides of aluminium, silicon and iron (Fe and 29.6%, output fraction - 76,5%). The magnetic fraction is subjected to gravitational enrichment to a concentration table HOLMAN obtaining hematite concentrate (Fe - 48,1%, the yield of the concentrate 15%) and tails (Fe - 35,8%, exit - 22%). Tails gravity separation combined with non-magnetic fraction obtained in the second stage high-gradient magnetic separation, and subjected to two-stage selective flocculation with the introduction of hydrolyzed polyacrylamide (SDS page - 3-5 g/t) in free-flow cyclone for separating light faction the component, consisting mainly of oxides of aluminum and silicon (Fe - 14,3%, the yield of fraction 20%), from iron-containing product (Fe - 30,9%, exit - 70%). Iron-containing product is enriched high-gradient magnetic separation at a field strength of 0.5-0.7 T magnetic separator "Humboldt" to retrieve sfokusirovannykh iron-bearing minerals with additional iron-containing product (Fe - 52,0%, output - 24%) and residual silicates (Fe - 20.9%, exit - 46%).

Additional iron-containing product combined with the hematite concentrate to produce iron concentrate (Fe - 50%, exit - 35%), which after filtering and drying, can be used in ferrous metallurgy.

Residual silicates combined with the component, which is the light fraction selective flocculation, obtaining aluminosilicate product (Fe - 22,3%, output - 65%), which can be used in the construction industry.

For an additional increase in the extraction of iron tails gravity separation prior to selective flocculation is subjected to screening to a particle size of minus 0,032 mm, and discordantly wet magnetic separation is carried out at a ratio W:T=3÷4:1.

The claimed method is tested in laboratory conditions. From red mud, sod is rzasa, %: Fe2O3of 45.4; A2O3- 13,8; SiO2- 10,10; CaO - 6,4 received iron-containing concentrate composition, %: Fetotal- 50,0; FeO - 10,8; Fe2O3- 53,1; And2About3- 11,4; SiO2- 7.62mm; CaO - 1,36, and aluminosilicate product composition, %: Fe - 22,3; FeO - 3,12; Fe2O3- 28,4; And2About3- 16,9; SiO2- 13,2; Cao - 12,6.

Output of iron ore concentrate, 35%, iron extraction - 54,7%.

1. Method for integrated processing of red mud containing hematite, chamosite, goethite, magnetite and silicates, by means of magneto-gravity processing of obtaining iron concentrate and alumina products, characterized in that the original red mud previously subjected to dispersion in the presence of sodium hexametaphosphate in a rotary pulsation apparatus, and then carry out discordantly wet magnetic separation field strength of 0.1-0.15 Tesla obtaining magnetite and collective concentrate bulk concentrate is subjected to high-gradient magnetic separation in two stages in the field of not less than 1.2 TL with removing the magnetic and nonmagnetic fractions, the magnetic fraction is subjected to gravitational enrichment to a concentration the table with the receipt of hematite concentrate and tailings, and the non-magnetic fraction combined with the tails of the gravitational abogada the Oia and subjected to two-stage selective flocculation in the presence of flocculant to separate component, consisting mainly of oxides of aluminum and silicon from iron-containing product, which enrich the high-gradient magnetic separation at a field strength of 0.5-0.7 T with additional iron-containing product, which combine with the hematite concentrate to produce iron concentrate and residual silicates, which unite with the component, consisting mainly of oxides of aluminum and silicon with getting aluminosilicate product.

2. The method according to claim 1, characterized in that discordantly wet magnetic separation is carried out at a ratio W:T=3÷4:1.

3. The method according to claim 1, characterized in that the sodium hexametaphosphate is used in the amount of 100-200 g/so

4. The method according to claim 1, characterized in that the tails of gravity separation prior to selective flocculation is subjected to screening to a particle size of minus 0,032 mm

5. The method according to claim 1, characterized in that as a flocculant use hydrolyzed polyacrylamide in the amount of 3-5 g/T.



 

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FIELD: waste treatment.

SUBSTANCE: multicomponent waste material is preliminarily impregnated with solution of salt of metal-collector in amount ensuring weight content of metal-collector in melt exceeding content of metallic components therein. Material is then calcined and melted in reductive atmosphere after addition of slag-forming flux based on metal fluorides. Melt is stirred and kept in liquid state over a period of time long enough to allow separation of slag and metallic phases. Resulting slag and metal are tapped and mechanically separated when solidified.

EFFECT: achieved high degree of recovering metals in collecting alloy at minimum expenses.

8 cl

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